The present invention pertains to a device for conveying separate objects, especially disk-shaped objects, such as coins, with a guideway and with a conveyor circulating on a conveying arm at a spaced location from the guideway, wherein the distance between a strand of the transport belt facing the guideway and the guideway is smaller than the smallest height of an object above the guideway, wherein the objects can be grasped by the strand of the conveyor facing the guideway and can be conveyed on the guideway and wherein the static friction and/or sliding friction forces between the objects and the conveyor are greater than the static friction and/or sliding friction forces between the objects and the guideway, as well as to applications of such a device. The objects that can be conveyed within the framework of the present invention usually have a disk shape, wherein one principal surface slides on the guideway and the opposite principal surface is grasped by the conveyor. A guideway may be designed, e.g., as a sorting plate.
A device of the design described in the introduction has been known, e.g., from the reference EP 0 616 303 B1 for conveying coins. The side of the transport belt facing the coins has a smooth surface here, at any rate without readily visible elevations. The pressure of the transport belt on the coins to be conveyed is applied by a plurality of support rollers which are subject to a spring force in the direction of the guideway and which are arranged along the conveying arm. Even though this design has proved basically successful, it has a plurality of drawbacks. It can be pointed out at first that the effort needed for mounting the conveying arm as well as the effort needed for adjusting the individual rollers are considerable. It is disturbing from a kinematic viewpoint that the pressure of the transport belt declines in the areas between the support rollers, which may be disturbing especially during the conveying of coins with greatly varying thicknesses in the case of the thin coins. Furthermore, the prior-art arrangement is also complex from a dynamic viewpoint because of the many spring-loaded support rollers, because a system with pronounced natural frequencies is thus created, which may lead to problems in light of the usual high conveying velocities. To avoid disturbing vibrations of the transport belt against the guideway, certain conveying velocities are therefore to be avoided or suitable damping measures are to be taken. Finally, it is disturbing that the springs of the support rollers may fatigue during long operation times, with the consequence that reliable conveying of even very thin coins is not always guaranteed.
In contrast, the basic technical object of the present invention is to provide a device for conveying separate objects which can be manufactured in a simple manner in terms of mounting and nevertheless guarantees the reliable conveying of objects of different thicknesses and it does so even during long operation times.
To accomplish this technical object, the present invention teaches that the conveyor is a lamella belt and that the strand of the lamella belt facing the guideway is guided over the entire longitudinal extension of the convening arm with the proviso that the distance dxe2x80x2 between the lamella tips pointing toward the guideway and the guideway is smaller than the smallest height of an object above the guideway.xe2x80x94A transport belt which has a continuous, especially uniform sequence of vertically or obliquely projecting lamellae on its side running against the guideway, which lamellae are arranged at a belt base, is called a lamella belt. The terms xe2x80x9clamella beltxe2x80x9d and xe2x80x9clamellaxe2x80x9d also cover within the framework of the present invention embodiments with knobs, e.g., of a cylindrical design, arranged regularly or irregularly, laterally (or at right angles to the longitudinal extension of the belt). The lamellae may be oblique against the direction of conveying or in the direction of conveying. The form of the lamellae is basically freely selectable. Centrally symmetrical lamellae with a triangular cross section (relative to a plane arranged at right angles to the guideway and extending in the direction of conveying) are preferred, the tips of the lamellae being rounded. The lamellae may extend at right angles to the direction of conveying in their extension at right angles to the direction of conveying (continuously) or may be set at a pitch angle in relation to the direction of conveying (in the case of the knobs, knob rows may be arranged at right angles or with a pitch angle). The latter arrangement, i.e., with a pitch angle, is advantageous, e.g., when the objects are to move on the guideway along a guide edge. In this case, the pitch angle, measured between the longitudinal extension of the transport belt and the transverse extension of the lamellae, namely, on the side in the direction of movement of the transport belt, is smaller than 90xc2x0, e.g., between 80xc2x0 and 89.5xc2x0. The term xe2x80x9clamellaxe2x80x9d implies within the framework of the present invention that these are rubber-elastic or elastic. The distance dxe2x80x2 can be selected in a range from 0 to a value slightly below the thinnest object to be conveyed. A range of 0 to 1 mm, preferably 0 to 0.5 mm and especially 0 to 0.1 mm is recommended for dxe2x80x2 in the case of coins.
Objects with very greatly varying thicknesses can be surprisingly conveyed with the present invention with very high reliability. Without wanting to be bound to a theory, the reason for this is presumably, especially in the case of thin objects, an effect supporting the conveying during the coming into contact of a lamella with an edge of an object standing opposite the direction of conveying. This object is now conveyed not only because of the friction effects of lamellae that are in contact, but the object is additionally quasi pushed. Furthermore, the use of a lamella belt according to the present invention makes it unnecessary to arrange a plurality of support rollers, which must press the smooth belt against the objects according to the state of the art, doing so with corresponding spring excursions in the case of varying thicknesses. Finally, the risk of fatiguing of the springs is therefore eliminated as well. It is also particularly advantageous that the present invention is suitable not only for horizontal conveying, but also for oblique and vertical conveying. Consequently, the longitudinal extension of the guideway may form any desirable angle with the horizontal direction. In particular, the angle between the guideway and the horizontal direction may be variable and preferably continuously variable over the course of the guideway. Consequently, curved guideways are also possible, besides flat guideways.
A preferred embodiment of the present invention is characterized in that at least the lamellae of the lamella belt, preferably the lamella belt as a whole (optionally with reinforcing inserts) is made of a material which is selected from the group comprising xe2x80x9celastomers, rubbers, natural rubber, synthetic rubber, polyurethane, polyether polyurethane, polyester polyurethane, rubber-elastic materials and mixtures of these materials.xe2x80x9d These lamella materials possess advantageous properties in terms of their rubber-elastic material properties as well as the friction forces occurring between the material and the objects. It is preferred in these connections for the lamellae to have a Shore A hardness of 50 to 100 and preferably 60 to 80 measured according to DIN 53505 (version: June 1987).
Concerning the geometric design, it is preferable for the height of the lamellae to be in the range of 2 to 20 mm, preferably 2 to 8 mm and especially 3 to 5 mm. The measure from a lamella base at the belt base to the tip of the lamella is called the height of the lamella. The density of the lamellae is preferably in the range of 100/100 mm to 10/100 mm and preferably 50/100 mm to 20/100 mm. The number of lamellae per 100 mm of lamella belt in its longitudinal extension or its unrolled circumference is called the lamella density. This also applies analogously to the knobs.
The lamella belt may be designed, in principle, as a V-belt which is structureless on its back side or as a flat belt. However, the lamella belt preferably has drive teeth opposite the lamellae, i.e., on the inside. In this case, the belt can be driven without slip by means of a toothed belt pulley with pulley teeth meshing the drive teeth.
For reasons of preventing disturbing stretching of the lamella belt, the lamella belt may have an endless steel wire insert. Instead of steel wire, reinforcement with other materials, e.g., woven threads or cords, may be provided as well. A wire or thread which extends helically over more than one full circumference of the lamella belt, preferably over at least 2 to 20 times and, e.g., 5 to 15 times the circumference is called xe2x80x9cendless.xe2x80x9d It is obvious that two ends are ultimately left in this case as well, but they are separated from one another by a plurality of endless turns.
Due to the elimination of the need for support rollers, the conveying arm may have a comparatively simple design. The conveying arm preferably has at least one guide element, which has a U- or H-shaped cross section in the longitudinal extension of the conveying arm, wherein the lamella belt is guided by webs on both sides laterally, relative to the lamella belt, and wherein the lamella belt slides on a support surface between the webs. In the case of the U-shaped cross section, the webs are, of course, arranged on the side facing the guideway. The lamella belt now runs without lateral guiding, e.g., freely swinging, on the opposite side of the conveying arm. The guide element consists, at least in the area of the support surface, preferably also in the areas of the webs, and everywhere for simplicity""s sake, of a material which is selected from the above-mentioned group of materials. The conveying arm preferably has deflecting rollers, preferably spur wheel-shaped deflecting rollers, at its end, with at least one of the deflecting rollers being able to be driven. Such rollers are also called toothed belt pulleys. It is specifically recommended that the support surface have a wedge-shaped inlet area on the inlet side. The conveying arm may have a base carrier on which the one guide element or a plurality of guide elements are arranged adjustably preferably at right angles to the guideway. Reliable setting and maintenance of the distance dxe2x80x2 over the entire longitudinal extension of the guide elements is thus guaranteed. Moreover, readjustment is easily possible in the case of worn lamella tips. Furthermore, it is recommended that at least one deflecting roller be able to be adjusted and fixed in the direction of the longitudinal extension of the conveying arm, as a result of which adjustment of the tension of the lamella belt is possible. In addition, the lamella belt can then be easily released to the extent that it can be easily pulled off from the conveying arm.
To ensure easy access to the guideway as well as accessibility for adjusting the guide elements as well as for changing the lamella belt, the conveying arm may be designed such that it can be pivoted off from the guideway on one side. In addition or as an alternative, the conveying arm as a whole may, of course, also be designed as a detachable conveying arm.
The conveying arm may have at least one adjusting element for setting the distance dxe2x80x2, as a result of which it is not necessary to readjust all guide elements individually after the adjustment of a plurality of guide elements, e.g., for readjustment or for changeover.
The present invention also provides for the use of a device according to the present invention for conveying coins in the horizontal and/or vertical and/or oblique direction, optionally with, e.g., segment-shaped transition areas.
The device according to the present invention may be used, in particular, in a device for counting and/or sorting coins. Reference is made in this connection to the relevant state of the art insofar as transport belts are used there. These transport belts and the conveying arms belonging to them can be easily replaced with devices according to the present invention.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.